High risk and low prevalence diseases: Ovarian torsion
a b s t r a c t
Introduction: Ovarian torsion is a rare, frequently misdiagnosed condition that carries with it a high rate of mor- bidity.
Objective: This review highlights the pearls and pitfalls of ovarian torsion, including presentation, evaluation, and management in the emergency department (ED) based on current evidence.
Discussion: Ovarian torsion is one of the most common gynecological Surgical emergencies and occurs with com- plete or partial rotation of the ovary along the supporting ligaments, obstructing vascular flow. Several risk fac- tors include the presence of an ovarian mass or cyst. The most common population affected includes reproductive aged women, though cases also occur in premenarchal females, pregnant women, and postmeno- pausal women. Abdominal or pelvic pain is common but is not always sudden in onset or severe. Nausea and vomiting occur in 70%. Ultrasound can assist with diagnosis, but a normal ultrasound examination cannot ex- clude the diagnosis. Computed tomography with intravenous contrast can assist with diagnosis. Treatment in- cludes emergent gynecologic consultation for surgical detorsion, along with symptomatic therapy in the ED. Conclusions: An understanding of ovarian torsion can assist emergency clinicians in diagnosing and managing this disease.
Published by Elsevier Inc.
This article series addresses high risk and low prevalence diseases that are encountered in the emergency department (ED). Much of the primary literature evaluating these conditions is not emergency medicine focused. By their very nature, many of these Disease states and clinical presenta- tions have little useful evidence available to guide the emergency physi- cian in diagnosis and management. The format of each article defines the disease or clinical presentation to be reviewed, provides an overview of the extent of what we currently understand, and finally discusses pearls and pitfalls using a question and answer format. This article will discuss ovarian torsion. This condition’s low prevalence but high morbid- ity, as well as its variable atypical Patient presentations and challenging diagnosis, makes it a high risk and low prevalence disease.
Ovarian torsion is one of the most common gynecologic surgical emergencies, typically affecting women between the ages of 29 to 34
* Corresponding author at: 3841 Roger Brooke Dr, Fort Sam Houston, TX 78234, USA.
E-mail address: Brit.long@yahoo.com (B. Long).
years [1-5]. It refers to the complete or partial rotation of an ovary along the supporting ligaments, resulting in partial or complete ovarian blood flow obstruction. While the incidence of adnexal torsion is largely unknown, data suggest ovarian torsion accounts for 2.7% of surgical emergencies, with torsion the 5th most common surgical emergency [6]. Another study found up to 15% of patients undergoing surgical treat- ment for adnexal masses were ultimately diagnosed with ovarian torsion [7].
Anatomically, the infundibulopelvic ligament suspends the ovary, which is movable and can be positioned laterally or posteri- orly in reference to the uterus (Fig. 1). The ovarian vasculature (i.e., ovarian artery) travels along this ligament [8]. The utero- ovarian ligament connects the ovary to the uterus and contains the vasculature from the uterine artery to the ovary. The ovaries and supporting ligaments are not fixed in position. Ovarian torsion is often associated with a pelvic abnormality such as an ovarian mass, which can increase rotation and movement along the liga- ments [2,8-10]. With torsion, the ovary will rotate around the infundibulopelvic and utero-ovarian ligaments. This can compress the ovarian vasculature, reducing lymphatic and Venous outflow as well as arterial inflow. Lymphatic and venous outflow are com- promised first due to thinner, more compressible vessel walls. Arte- rial perfusion with blocked venous outflow results in edema and
https://doi.org/10.1016/j.ajem.2022.03.046 0735-6757/Published by Elsevier Inc.
Fig. 1. Ovarian Vascular Anatomy. From https://commons.wikimedia.org/wiki/File:Gray1170.png
ovarian enlargement, further worsening compression of the vascu- lature and leading to reduced arterial inflow, ischemia, and necrosis [4,5,8,11].
Diagnosis of ovarian torsion can be challenging. Most patients with ovarian torsion present with abdominal and/or pelvic pain, which are common ED complaints. However, this is not always the case. All ages may be affected, and imaging for diagnosis does not possess 100% sensitivity [1,8,11-15]. Unfortunately, if the diagnosis is missed, torsion can result in necrosis of the involved ovary, reduc- ing fertility [5,6,16].
Patients with ovarian torsion can present with a variety of signs and symptoms. The classic presentation of ovarian torsion is sudden, severe, unilateral, lower abdominal or pelvic pain with nausea and vomiting in a women of reproductive age in the setting of a risk factor such as an ovarian mass or prior ovarian torsion [1,2,4,5,7,11,15,17-23]. Symptoms may be continuous or intermittent. Physical examination may reveal fever, lower abdominal pain, pelvic tenderness, and pelvic mass [2-5,18,19,24,25].
There is no confirmatory laboratory test, and laboratory findings are typically non-specific [5,6,16]. Imaging is an important component of ED evaluation [8,15,18,26]. While a pregnancy test should be obtained, it should not delay imaging if ovarian torsion is suspected. Transvaginal Ultrasonography is classically considered the first-line imaging modality in adults (transabdominal in pediatric patients), which may reveal a rounded, enlarged ovary due to edema and vascular and lym- phatic enlargement (Fig. 2) [11,13,15,18,26-29]. The affected ovary may be displaced towards the midline and demonstrate peripherally displaced follicles with an afollicular stroma [11]. Doppler evaluation may show reduced or absent vascular flow [30-35]. The whirlpool sign demonstrating a twisted vascular pedicle can be diagnostic [28,36-39].
Other imaging modalities include magnetic resonance imaging (MRI) and computed tomography (CT) [8,12-15,39-45]. CT of the abdomen/ pelvis may demonstrate an enlarged ovary, uterine deviation towards the affected ovary, smooth wall thickening of cystic mass, ascites, and fallopian tube thickening (Fig. 3), while MRI can further characterize soft tissue and pelvic pathology in pediatric patients with equivocal US [8,15,26,46,47]. Direct visualization in the operating suite is the definitive diagnostic evaluation.
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- ED management
Ovarian torsion is a time-sensitive emergency, and the gold standard treatment is surgical detorsion through laparoscopy or laparotomy [18,29,48-53]. If the clinician suspects ovarian torsion, emergent consultation with the gynecology specialist is recommended, as the time to detorsion affects the risk of necrosis and ovarian viability [4-6,16,18,52,53]. Laboratory and imaging evaluation should not delay consultation if the clinician suspects ovarian torsion [18,52]. While awaiting surgical intervention, symptomatic therapy with antiemetics and analgesics is recommended.
- Pearls and pitfalls
- What risk factors are associated with ovarian torsion?
Several risk factors are associated with ovarian torsion, which when present should prompt consideration of the condition. The most com- mon risk factors are presence of ovarian mass or cyst, especially those greater than 5 cm, and prior pelvic surgery, especially previous torsion and tubal ligation [1,8,18,20,54]. While the 5 cm delineator confers greater risk, torsion has been reported in masses ranging from 1 to 30 cm with an average of 9.5 cm, highlighting that torsion can occur with any sized mass [4]. Additionally, women undergoing ovulation in- duction for infertility treatment as well as women with polycystic ovar- ian syndrome may experience enlarged ovarian cysts, placing them at increased risk for ovarian torsion [20,55]. In the premenarchal popula- tion, those with elongated infundibulopelvic ligaments are at risk for in- creased rates of torsion [56-58].
Fig. 2. US demonstrating ovarian edema, peripherally oriented follicles, and no venous or arterial flow. Case courtesy of Dr. Maulik S Patel, Radiopaedia.org, rID: 30458.
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- What ages may be affected?
Ovarian torsion can affect women of all ages, with the average age occurring around 30 years old; however, a significant proportion of cases occur in premenarchal, postmenopausal, and pregnant patients
Fig. 3. CT demonstrating twisted ovarian pedicle and ovarian edema (yellow arrow), diag- nostic of ovarian torsion. Case courtesy of RMH Core Conditions, Radiopaedia.org, rID: 28265.
[3,4,16,18,19]. In premenarchal patients, the average age of those pre- senting with torsion is 10 years old, and over half of these patients will have normal ovaries on intraoperative laparoscopy [3,59,60]. How- ever, torsion tends to occur more frequently with benign masses or cysts, with less than 2% found to be malignant [1,5]. Due to increased progesterone during the first trimester of pregnancy, pregnant women account for 10-22% of cases, with a peak incidence at 10-17 weeks ges- tation with cysts greater than 4 cm [3-5,61,62]. As compared to their pregnant counterparts, non-pregnant women with cysts 4 cm or greater have a 1-6% lower incidence of torsion [63,64]. Postmenopausal pa- tients account for approximately 15% of cases, with almost all cases in this age group associated with an enlarged ovary or pelvic mass [3,5,7,14,16,30,61,62].-
- What are the limitations of the history and examination?
Clinicians classically associate ovarian torsion with sudden onset, unilateral abdominal pain refractory to analgesia, though historical and physical examination factors carry more nuances and limitations. The pain experienced in the setting of ovarian torsion occurs secondary to occlusion of the vascular pedicle. While this is commonly associated with acute abdominal pain radiating to the inguinal or flank area with nausea and vomiting, only 50% of patients will experience sudden, severe abdominal pain [5,16,18,19,24,65]. The description and type of pain vary widely, but 90% experience some form of pain which may be acute, chronic, or episodic. This finding also underscores that at least 10% of patients with torsion will have painless torsion [5,16,19,24,65-67]. Nausea and vomiting are present in up to 70% of patients, but up to 30% do not have these symptoms. Pain, nausea, and vomiting may be constant or episodic if torsion occurs intermittently [4,5,16,18,24,66,67]. In 2-20% of patients, fever may be present, further increasing the diagnostic challenge [3,5,16,19,24,66,67]. The historical features in infants are even more challenging as they may present with feeding intolerance, fussiness, or irritability, while older pediatric patients may present with fever and diffuse abdominal pain which can delay diagnosis due to the wide differential of conditions associated with these symptoms [3,16,19,60,65,68].
Physical examination can be similarly vague and misleading, as up to one third of patients may not have abdominal or pelvic tenderness on
palpation [2-5,16,18,24]. Based on the available literature, while ovarian cysts increase the risk of torsion, these cysts are not often found on physical examination when assessing for adnexal tenderness or fullness with an interrater reliability of 23-32% which persists when the exam- ination is performed by a gynecologist [16,25,69]. With a mass greater than 5 cm, gynecologists’ sensitivity for detecting this sized mass is 15-36% [16,25,69]. Adding to the difficulty, the examination is even less reliable in older patients greater than 55 years and patients exceed- ing 200 lbs. [70]
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- What imaging modalities may be used for diagnosis, and what are their limitations?
US is considered the primary imaging modality in evaluation of ovar- ian torsion, though a normal ultrasound cannot effectively rule it out [15,16,18,39]. In pediatric females, transabdominal US with a full blad- der is the initial Imaging study of choice to evaluate for torsion. The sen- sitivity of transabdominal US in pediatric and Adolescent patients is 92-93%, with a specificity of 96-100% [71]. In adult females, transvaginal US demonstrates excellent specificity but variable sensitiv- ity, ranging from 35 to 85% [8,12,13,15,18,31]. The most common sign of torsion on US is ovarian enlargement secondary to edema though other signs may include “string of pearls” sign where peripheral follicles surround the ovary, as well as midline displacement of the ovary [12-14,16,31,72]. Additionally, the whirlpool sign increases true posi- tive rates of diagnosis while free pelvic fluid improves sensitivity [16,36,38,39]. On doppler, US may demonstrate absent or decreased ovarian venous flow, while absent arterial flow may develop in later dis- ease [8,12-16,31,72]. Of note, normal vascular flow on US does not rule out ovarian torsion because of the dual ovarian vascular supply [13,16]. Torsion typically first reduces venous and lymphatic vascular outflow, with arterial flow affected later in the disease course [4,6,16]. In fact, up to 25% of patients with laparoscopically confirmed torsion will have normal arterial flow on US, and more than half will demonstrate detectable arterial flow [14,30,31,72]. Combining findings may improve US accuracy and reliability. A combination of free fluid in the pelvis, en- larged ovary, and vascular flow abnormalities increase the sensitivity and specificity of US [16].
CT of the abdomen and pelvis with IV contrast possesses significant
utility in the evaluation of suspected torsion, demonstrating both high specificity and sensitivity [8,12,14,15,18,41,73-75]. Various findings that are highly specific for ovarian torsion on CT include reduced or ab- sent ovarian enhancement with contrast, peripherally displaced folli- cles, enlarged ovary with a follicular ovarian stroma, and a thickened fallopian tube with target/beak-like appearance [12,14,41,73-75]. Fea- tures that are not specific but may suggest torsion include periovarian fat stranding, adnexal wall thickening, free pelvic fluid, ovarian mass or enlargement, ovarian displacement towards the uterus, and uterine deviation towards the torsed ovary [12,14,41,73-75]. In CT without these features, sensitivity approaches 100% for ruling out torsion [12,14,41,73-75].
Minimizing overall Ischemic time remains a key component of ther- apy, but the time to necrosis in ovarian torsion is unclear based on the current literature [18,52,53,76]. Since venous and lymphatic flow are af- fected first, patients may have symptoms for a significant period of time before arterial flow is affected [16,76,77]. Ovarian salvage has been doc- umented up to 36 h in pediatric patients [60]. In a retrospective study of pediatric ovarian torsion, the mean time to salvage with detorsion was
10.8 h, with all salvaged cases undergoing operative detorsion within the first 24 h in 27% of patients [60]. If the patient underwent detorsion within 8 h, the salvage rate was 40% while those who received operative intervention within 24 h had a salvage rate of 33%. However, no patients over 24 h had successful ovarian salvage on detorsion [60]. This rate is
Table 1
Summary of pearls.
-
-
- Crucial risk factors for ovarian torsion include the presence of an ovarian mass or cyst and prior pelvic surgery.
- Ovarian torsion most commonly affects reproductive-aged women, but a significant proportion of cases occur in premenarchal females, pregnant women, and Postmenopausal women.
- Up to 90% of women experience abdominal pain, but this is not always sudden in onset and severe. Pain can be gradual and episodic. Up to 70% experience nausea and vomiting.
- Up to one-third of patients with torsion have no abdominal or pelvic tenderness on examination.
- While ultrasound is considered the primary imaging modality in evaluation of ovarian torsion and possesses high specificity, a normal ultrasound cannot effectively rule out the diagnosis.
- CT of the abdomen and pelvis with IV contrast can assist in the diagnosis, evaluating for reduced or absent ovarian enhancement with contrast, peripherally displaced follicles, enlarged ovary with a follicular ovarian stroma, and a thickened fallopian tube with target/beak-like appearance.
- While time is ovary, emergent gynecologic consultation is recommended, as there is no clear time to necrosis in ovarian torsion.
-
consistent with that of adult females with 30% salvage for those who re- ceived operative intervention within 24 h of symptom onset [78,79]. A retrospective study demonstrated a median time to diagnosis from the time of presentation of 12 h, but the median time from symptom onset to presentation approximated 3 days (range 0-60 days) [5]. An- other study found the median time from symptom onset to surgical detorsion was 16 h, with a range between 2 and 144 h [50]. A 12-year retrospective analysis found the mean time from ED triage to surgery was 15 h, while nonviable ovaries had a mean time to surgery of 30 h [80]. Both pediatric and adult ovarian torsion patients additionally show good long term outcomes of detorsing hemorrhagic or ischemic- appearing ovaries, with 90-94% producing normal follicles [23,81,82]. Other Pediatric case series demonstrate variable salvage rates, as a se- ries of 51 pediatric patients who were all evaluated after 8 h of symptom duration did not demonstrate any successful salvage [22]. Reducing is- chemic time from symptom onset to detorsion is optimal in managing ovarian torsion, and there is no clear single time after which ovaries are not salvageable [52,53]. Thus, emergent specialist consultation is recommended, no matter the patient’s time of symptoms.
Table 1 demonstrates pearls and pitfalls in the evaluation and man-
agement of ovarian torsion.
- Conclusions
Ovarian torsion occurs with complete or partial rotation of the ovary, resulting in obstruction of vascular flow. There are several risk factors associated with the disease, including the presence of an ovarian mass or cyst. Reproductive aged women are the most common patients af- fected, though cases also occur in premenarchal females, pregnant women, and postmenopausal women. Abdominal or pelvic pain is com- mon but is not always sudden in onset or severe. Nausea and vomiting occur in 70%. Ultrasound can assist with diagnosis and is specific, but its sensitivity precludes its use to exclude the diagnosis. CT with IV con- trast can assist with diagnosis. Emergent gynecologic consultation for surgical detorsion is recommended, along with symptomatic therapy in the ED.
CRediT authorship contribution statement
Rachel E. Bridwell: Writing – review & editing, Writing – original draft, Visualization. Alex Koyfman: Visualization, Conceptualization, Supervision, Validation. Brit Long: Writing – review & editing, Writing – original draft, Supervision, Conceptualization.
Declaration of Competing Interest
None.
Acknowledgements
BL, RE, and AK conceived the idea for this manuscript and contrib- uted substantially to the writing and editing of the review. This manu- script did not utilize any grants, and it has not been presented in abstract form. This clinical review has not been published, it is not under consideration for publication elsewhere, its publication is approved by all authors and tacitly or explicitly by the responsible authorities where the work was carried out, and that, if accepted, it will not be published elsewhere in the same form, in English or in any other language, includ- ing electronically without the written consent of the copyright-holder. This review does not reflect the views or opinions of the U.S. govern- ment, Department of Defense, U.S. Army, U.S. Air Force, or SAUSHEC EM Residency Program.
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